Solar power generation is divided into concentrated solar power (CSP) and photovoltaic (PV). Regardless of production volume, development speed, or future prospects, CSP cannot match PV. Perhaps because PV is more widespread, people are less familiar with CSP; therefore, when people talk about solar power, they usually mean solar photovoltaic (PV) power, or simply photovoltaic.
A home solar power system consists of solar panels, a solar controller, and a battery (or battery bank). If the output power is AC 220V or 110V, an inverter is also required.
I. Solar Panels
Solar panels are the core component of a solar power generation system. Their function is to convert sunlight into electrical energy, outputting direct current (DC) which is then stored in batteries. Solar panels are one of the most important components of a solar power generation system; their conversion efficiency and lifespan are crucial factors determining the usability of a solar cell. Module design: Designed according to the International Electrotechnical Commission (IEC) standard 1215:1993, it uses 36 or 72 polycrystalline silicon solar cells connected in series to form various types of 12V and 24V modules. This module can be used in various residential photovoltaic systems, stand-alone photovoltaic power plants, and grid-connected photovoltaic power plants.
Characteristics of solar panel raw materials:
Solar cells: High-efficiency (above 16.5%) monocrystalline silicon solar cells are used to ensure sufficient power generation of the solar panels.
Glass: Low-iron tempered textured glass (also known as clear glass) is used, with a thickness of 3.2mm. It boasts a light transmittance of over 91% within the wavelength range of solar cell spectral response (320-1100nm) and high reflectivity for infrared light greater than 1200nm. This glass is also resistant to solar ultraviolet radiation without any decrease in light transmittance.
EVA: A high-quality EVA film layer with a thickness of 0.78mm, containing UV stabilizers, antioxidants, and curing agents, is used as a sealant for solar cells and as a bonding agent between the solar cells and glass/TPT. It has high light transmittance and anti-aging properties.
TPT: The fluoroplastic film covering the back of the solar cell is white and reflects sunlight, thus slightly improving the efficiency of the module. Its high infrared emissivity also reduces the module's operating temperature, further contributing to improved efficiency. Of course, this fluoroplastic film must first meet the basic requirements of solar cell encapsulation materials, such as aging resistance, corrosion resistance, and air impermeability.
Frame: The aluminum alloy frame used has high strength and strong resistance to mechanical impact. It is also the most valuable part of a residential solar power system.
II. Solar Controller
A solar controller consists of a dedicated CPU, electronic components, a display, and switching power transistors.
Key features of solar controllers:
1. Intelligent control was achieved by using a microcontroller and dedicated software;
2. Accurate discharge control corrected by the battery discharge rate characteristics. The discharge termination voltage is a control point corrected by the discharge rate curve, eliminating the inaccuracy of over-discharge caused by simple voltage control. This conforms to the inherent characteristics of the battery, namely that different discharge rates have different termination voltages.
3. Features fully automatic control including overcharge, over-discharge, electronic short circuit, overload protection, and unique reverse connection protection; all of these protections do not damage any components or blow fuses.
4. The series-connected PWM charging main circuit reduces voltage loss in the charging circuit by nearly half compared to diode-based circuits, resulting in 3%-6% higher charging efficiency and extended charging time. Over-discharge recovery boost charging, normal direct charging, and automatic float charging control extend the system's lifespan. It also features high-precision temperature compensation.
5. The intuitive LED indicator shows the current battery status, allowing users to understand the usage status;
6. All controls utilize industrial-grade chips (only for industrial-grade controllers with I-band), enabling smooth operation in cold, high-temperature, and humid environments. Crystal oscillator timing control is also employed, ensuring precise timing.
7. The potentiometer adjustment control setpoint has been eliminated, and instead, an E-square memory is used to record each working control point, making the settings digital and eliminating factors that reduce accuracy and reliability due to potentiometer vibration deviation, temperature drift, etc.
8. Utilizing digital LED display and settings, all settings can be completed with a single button, making it extremely convenient and intuitive to use. Its function is to control the overall system's operating status and provide overcharge and over-discharge protection for the battery. In environments with significant temperature differences, a qualified controller should also have temperature compensation functionality. Other additional functions such as light-controlled switches and time-controlled switches should be optional features of the controller.
III. Storage Battery
The function of a storage battery is to store the electrical energy generated by solar panels when there is sunlight, and release it when needed. Solar storage batteries are the application of 'storage batteries' in solar photovoltaic power generation, and four types are used: lead-acid maintenance-free batteries, ordinary lead-acid batteries, gel batteries, and alkaline nickel-cadmium batteries. The most widely used solar storage batteries in China are lead-acid maintenance-free batteries and gel batteries. These two types of batteries are well-suited for reliable solar power systems, especially unattended workstations, due to their inherent maintenance-free characteristics and low environmental pollution.
IV. Inverter
Solar power typically outputs 12VDC, 24VDC, or 48VDC directly. To power appliances operating at 220VAC, the DC power generated by the solar power system needs to be converted into AC power, thus requiring a DC-AC inverter.
